MOSCOW • Russia's President Vladimir Putin has phoned his US counterpart Donald Trump to thank him for a tip from the CIA that thwarted a terrorist attack being planned in St Petersburg.

The unusual call - countries share intelligence all the time, but presidents rarely publicly thank one another for it - was confirmed by White House spokesman Sarah Sanders.

Mr Putin told Mr Trump on Sunday that the information provided by the Central Intelligence Agency (CIA) allowed Russian law enforcement agencies to track down and detain a group of suspects who were planning to bomb the centrally located Kazan Cathedral and other crowded parts of Russia's second-largest city.

"Based on the information the United States provided, Russian authorities were able to capture the terrorists just prior to an attack that could have killed large numbers of people," the White House said in its read-out of the call.

"Both leaders agreed that this serves as an example of the positive things that can occur when our countries work together."

It was the two presidents' second conversation since Thursday, when they spoke after Mr Putin's annual four-hour televised news conference, during which the Russian leader mentioned the booming US stock market as an example of Mr Trump's successes.

The White House said Mr Trump thanked Mr Putin for remarks he made "acknowledging America's strong economic performance".

Mr Putin said he doubted Mr Trump would be able to improve relations between their two countries because the US President was being held back by his political opposition, and allegations of Russian interference in the 2016 US election were being invented to raise doubts about Mr Trump's legitimacy.

The CIA tip apparently provided the breakthrough that allowed the Russian authorities last week to detain seven members of what officials identified as Islamic State in Iraq and Syria cells.

The suspects, investigators said, had been planning a suicide bombing last Saturday in Kazan Cathedral, a St Petersburg landmark located on Nevsky Prospect, its main thoroughfare. The cathedral was built between 1801 and 1811, and was designed along the lines of a Roman Catholic basilica.

Russian state television reported the capture of the alleged cell members, as it often does in takedowns of terrorist suspects, with a video that shows agents in action and an on-camera confession.

In this case, a man identified as Yevgeny Yefimov confessed that he planned to carry out an attack in the city. Later, Yefimov told a St Petersburg court he was planning to target the Kazan Cathedral. Three more people were arrested on Sunday in connection with the alleged plot, RIA Novosti reported.

WASHINGTON POST